Lamb Chops with Greens and Sorrel Salsa Verde

Name: Lamb Chops with Greens and Sorrel Salsa Verde
Ingredients: 8 1½–2-thick lamb loin chops (about 3 pounds); Kosher salt and freshly ground black pepper; ⅔ cup sorrel or spinach leaves; ⅓ cup mint leaves; ⅓ cup parsley leaves; 1 tablespoon finely grated lemon zest; 1 teaspoon crushed red pepper flakes; 5 garlic cloves, thinly sliced, divided; ⅓ cup plus 2 Tbsp. olive oil; 4 ounces king oyster or maitake mushrooms, cut into ½ pieces; 1 shallot, thinly sliced; 1 bunch mustard greens, ribs and stems removed, leaves torn into pieces; 1 tablespoon white balsamic vinegar; 1 tablespoon fresh lemon juice (add up to 3 total if using spinach)